This is a NIOSH Mentored Research Scientist Development Award (K01) grant proposal intended to promote the career of Dr. Christopher D. Heaney, PhD, MS, a W.K. Kellogg Health Scholar-Community Track post- doctoral fellow at the University of North Carolina, into an independent health scientist. I am a trained epidemiologist and microbiologist with a significant track record of research in community-based participatory research (CBPR) and environmental epidemiology. My goal is to integrate my existing experience with focused training in microbiology, immunology, and the molecular epidemiology of zoonotic pathogens, to become an independent scientist at the interface of basic science, occupational health practice, and population research. The topical area for the proposed career development is integration of bench science with methods for observational panel studies and CBPR. New disciplinary training will be integrated into my existing track record of CBPR with livestock workers and household members in NC to study the temporal nature of relationships between livestock exposure, zoonotic pathogen carriage, and symptoms of subclinical colonization versus infection. During this mentored award, I will expand my clinical microbiology and immunology training and epidemiologic research skills through mentorship from zoonotic infectious diseases physicians, clinical immunologists, microbiologists, and occupational health epidemiologists; engagement in formal didactics; attending multidisciplinary seminars, journal clubs, and scientific meetings; participation in study activities with my mentors; and by leadership of a project that integrates non-invasive zoonotic pathogen biomarkers into a community-based participatory panel study. These activities will be supervised by primary mentor Dr. David Weber MD, MPH, Director of the Occupational Health Services Clinic at UNC Hospitals and Professor of Epidemiology, Medicine, Pediatrics, and Infectious Diseases and co-mentor Dr. John Schmitz, PhD, Associate Director of Clinical Microbiology/Immunology and Associate Professor of Pathology and Laboratory Medicine at the UNC School of Medicine. My mentor, co-mentor, collaborators, and advisory committee members will supplement my training with their complementary expertise, and together are fully committed to helping me reach my higher disciplinary research training and career development goals, and ensuring my successful transition from mentored to independent research scientist. During year 1, I will meet weekly with mentors Drs. Weber and Schmitz to develop, optimize and validate an ELISA for detection of hepatitis E virus (HEV) antibodies (anti-HEV) in saliva. For this purpose co-mentor Dr. Schmitz is making available laboratory facilities and equipment to run ELISAs and de- identified saliva and serum for anti-HEV optimization and spiking experiments. In year 1, I will also visit collaborator Lance Price, PhD, Director of the Center for Microbiomics and Human Health at TGen, North, to continue training in multi-locus sequence typing (MLST) and whole genome SNP analysis (WGSA) of multidrug-resistant Staphylococcus aureus (MDRSA) isolated from nasal swabs of livestock workers and household members in an ongoing cross-sectional CBPR pilot study I am leading. For this purpose collaborator Price is making available his laboratory during my visit for training. During years 1 and 2, I will expand a CBPR partnership I initiated with collaborator Devon Hall of the Rural Empowerment Association for Community Help (REACH) - from a CBPR cross-sectional MDRSA prevalence study among livestock workers and household members to a community-based participatory panel study among livestock workers and household members in NC. The CBPR panel study will involve 200 livestock worker and household member participants with baseline and biweekly follow-ups for a period of 4 months. In years 2 and 3, I will meet weekly with Drs. Weber and Schmitz and collaborators to integrate the salivary anti-HEV ELISA and MDRSA genotyping methods (MLST and WGSA) into the CBPR panel study. Dr. Weber (primary mentor) and Stanley Lemon, MD (advisory committee member and Professor of Medicine and Infectious Diseases at UNC) have agreed to assist with medical referral and follow-up of CBPR panel study participants who develop symptoms of MDRSA and/or HEV infection after notification of carriage status (see plan in Protection of Human Subjects). With the support of my mentor, co-mentor, and collaborators, I am uniquely positioned to complete the proposed activities which build upon a strong CBPR partnership with IRB-approved protocols from an already-funded CBPR cross-sectional MDRSA prevalence study in NC. This information base will build a foundation to collect CBPR panel study data to characterize the temporal variation of livestock exposure, pathogen carriage, and symptoms of sub-clinical colonization versus infection - which will greatly improve current estimates of the burden of zoonotic pathogen exposure in livestock workers and household members in a region with intensive livestock production - NC. The proposed research is both novel and innovative because of its potential to advance causal inference in observational epidemiologic research, identify key risk factors of zoonotic pathogen exposure and points of intervention to reduce exposures and infection risks, and further promote the integration of CBPR with epidemiologic research15 to inform policy-making. The short-term benefits from this study will be a contribution to the under-studied area of the temporal trends and burden of two emerging zoonotic pathogens in livestock workers and household members. The long-term benefits will be translation of basic science methods for non-invasive measurement of zoonotic pathogens in nasal and saliva swabs from the bench to community to inform occupational health policies related to food animal production.